In storage systems, a storage management apparatus may be used, which provides functions including managements of the storage apparatuses, such as configuration managements, failure managements, and performance information managements of the storage apparatuses. Such a storage management apparatus manages the storage environment in a comprehensive manner, thereby achieving reliable operations of a storage system.
In a storage management apparatus, for example, performance information on conventional storage apparatuses and the like are graphically displayed, thereby providing users with information usable for optimizing input/output (I/O) performances defined in business requirements and allowing thresholds to be set to apparatuses and volumes for monitoring. This allows the users to be aware of any performance problems and to take countermeasures before the problems will affect on operations.    Patent Document 1: Japanese Laid-open Patent Publication No. 2017-103580    Patent Document 2: Japanese Laid-open Patent Publication No. 2004-30491    Patent Document 3: International Publication Pamphlet No. WO 2015/107574    Patent Document 4: Japanese Laid-open Patent Publication No.
05-313984    Patent Document 5: Japanese Laid-open Patent Publication No. 10-27127    Patent Document 6: Japanese Laid-open Patent Publication No. 11-7401    Patent Document 7: Japanese Laid-open Patent Publication No.
2015-60275    Patent Document 8: Japanese Laid-open Patent Publication No. 2015-92420
In recent years, as for storage apparatuses, researches have been conducted on software defined storages (SDSs), and development of new scale-out storage apparatuses has been proceeding, for example.
For managing the storage environment of a storage system by a storage management apparatus in a comprehensive manner, it is effective to enable collections of performance information from scale-out storage apparatuses, as well as collections of performance information from conventional storage apparatuses.
Application of performance information obtainment processing that has been carried out on conventional storage apparatuses, to scale-out storage apparatuses in a storage management apparatus, however, may cause the following disadvantages.
(a) Excessive Network Load Caused by Increased Volume of Data Obtained from Apparatuses
A storage management apparatus obtains the latest values of performance data (performance data items) in binary format from a storage controller that controls storage apparatuses, calculates statistics (e.g., differences and sums), writes them in files in a text format to retain as performance information, for example. Data lengths of binary performance data items are four or other bytes for integer data types, or are eight or other bytes for double precision data types, for example. An example of the text format includes comma separated values (CSV) format, for example.
The size of performance data increases as the number of parts (e.g., volumes) configuring a storage apparatus increases. For a scale-out storage apparatus having the maximum number of parts (about 65,000 parts) allowed in the specification, the size of performance data obtained from such a scale-out storage apparatus during a single obtainment may exceed 50 megabytes. Accordingly, in scale-out storage apparatuses, communication delays and the like may frequently occur due to congestions on networks caused by transfer of large volume data, which may make a management of the entire system by a storage management apparatus difficult.
(b) Consumption of Excessive Disk Space for Saving CSV Files.
A storage management apparatus obtains a performance data record that has been retained in a storage controller in programmably-computable binary format, and converts it into strings in CSV format for retaining the record. As a result, data is retained redundantly, which contributes to a lower storage efficiency.
For example, considering scale-out storage apparatuses in the maximum configuration, a storage management apparatus collects a record of 50 megabytes in every cycle of obtainment processing (e.g., in every 600 seconds), and retains the record during a preservation duration (e.g., 90 days). In this case, disk space of as much as 700 gigabytes will be occupied, and hence the usage of storing areas in the storage management apparatus will increase.
(c) Occurrence of Load for Deletion Processing for Data Outliving Beyond a Preservation Lifetime.
For example, performance information (performance information items) has a preservation lifetime such that a storage management apparatus searches the file system for CSV files having performance information items outliving beyond the preservation lifetime, to delete the expired CSV files. As a result, as the number and the data sizes of files of performance information increase, the processing load on the storage management apparatus for the deletion processing of the performance information increases.
As set forth above, depending on the scales (configurations) of storage apparatuses, obtainment processing of performance information from storage apparatuses by a storage management apparatus may become inefficient.